Air quality monitor



FIG. 1 is a front elevational view of an air quality monitor showing my new design;

FIG. 2 is a right side elevational view thereof, with the left side elevational view being a mirror image;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a rear elevational view thereof. 

The ornamental design for an air quality monitor, as shown and described. 